Novel polysiloxane compound and method of preparing the same



Patented Jan. 15, 1952 NOVEL POLYSILOXANE COMPOUND AND METHOD OFPREPARING THE SAME Robert 0. Sauer, Schenectady, N. Y., assignor toGeneral Electric Company, a corporation of New York No Drawing.Application January 22, 1948, Serial No. 3,837

4 Claims. I

This invention relates to a novel chemical compound and moreparticularly is concerned with the compound2,2,4,4,6,6,8,3-octamethyl-l,5-di oxa-2,4,6,8-tetrasilocane having theformula (CHahP-CHzP-KCHa);

and a method of preparing the same.

The claimed compound has utility as an intermediate in the preparationof other chemical compounds and higher molecular weight materials. Thiscompound is particularly useful in the preparation of higher molecularweight polymeric materials which may be used for lubricating purposes.For example, the compound embraced by my claimed invention may be causedto react with hexamethyldisiloxane in the presence of sulfuric acid inaccordance with the procedure disclosed and claimed in Patnodeapplication Serial No. 463,815, filed October 29, 1942, now abandoned,and assigned to the same assignee as the present invention, to yielduseful,

linear, liquid polymeric compositions of matter having utility aslubricants.

Various methods may be employed for preparing the claimed composition ofmatter. One method for preparing the above-identified silocane compriseshydrolyzing with an amount of Water in excess of that required forcomplete hydrolysis a compound corresponding to the general formulawhere X is a halogen, e. g., chlorine, bromine, fluorine, etc., andthereafter isolating the claimed silocane from the hydrolysis mass, forexample. by fractional distillation. A particular method for preparingthe aforementioned halogen-terminated silyl methanes is found in mycopending application, Serial No. 3,836, now Patent No. 2,491,833, filedconcurrently herewith and assigned to the same assignee as the presentinvention.

In order that those skilled in the art may better understand how theclaimed composition of matter may be prepared, the following example isgiven by way of illustration.

Example To an Aminco steel hydrogenation bomb was charged 855 gramstrimethylchlorosilane and about 23 parts anhydrous aluminum chloride.

The bomb was closed and the mixture heated at 375 C. and 1200 p. s. i.for 7 hours. After cooling the bomb, the liquid contents were fractionally distilled to yield a fraction comprising essentially purebis-(dimethylchlorosilyl) methane boiling at about 176-177 C. at 754 mm.Analysis of the compound showed it to contain 35.55 per cent chlorine(calculated 35.25 per cent). This compound has the following properties:

n 1.44.80 (Z4 1.016 Molar refractivity 53.01 (calculated 53.10)

tionally distilled to yield 2,2,4,4,6,6,8,8-octameth-'yl-1,5-dioxa-2,4,6,8-tetrasilocane having a melting point ofapproximately 30 C. and a boiling point of 213-215 C. This compound hasthe following additional physical properties:

n 1.4341 424 0.9039 Specific refraction 0.2882 (calc. 0.2888) Analysisof this compound showed it to comprise the following:

Found Calculated Per Cent Carbon 41. 2 41.05 Per Cent Hydrogen 9. 7 9.58

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. The method of preparing 2,2,4,4,6,6,8,8-octamethyl-1,5-dioxa-2,4,6,8tetrasilocane which comprises (1) hydrolyzing with an amount of water inexcess of that required for complete hydrolysis a compound correspondingto the general formula where X is a halogen and (2) isolating theaforementioned silocane.

2. The method of preparing 2,2,4,4,6,6,8,8-oc- 3tamethyl-1,5-dioxa-2,4,6,8 tetrasilocane which comprises (1) hydrolyzingbis-(chlorodimethylsilyl) methane with an amount of water in excess ofthat required for complete hydrolysis of the latter compound and (2)isolating the aforementioned silocane from the hydrolysis mixture.

3. The method of preparing 2,2;4,4,6,6,8,8-'octamethyl-1,5-dioxa-2,4,6,8 tetrasilocane whichcomprises (1) hydrolyzing a compound corresponding to the generalformula CH: CE;

x- 1-0H iX H; w H;

where X is a halogen and (2) isolating the aforementioned silocane.

REFERENCES CITED The following references are of record in the file ofthis patent:

Goodwin: J. A. C. 8., vol. 69 (1947), page 2247.

1. THE METHOD OF PREPARING2,2,4,4,6,6,8,8-OCTAMETHYL-1,5-DIOXA-2,4,6,8 - TETRASILOCANE WHICHCOMPRISES (1) HYDROLYZING WITH AN AMOUNT OF WATER IN EXCESS OF THATREQUIRED FOR COMPLETE HYDROLYSIS A COMPOUND CORRESPONDING TO THE GENERALFORMULA